Trans-halo(acyl)bis(triethylphosphine)nickel(II) complexes and preparation thereof

ABSTRACT

trans-Halo(acyl)bis(triethylphosphine)nickel (II) complexes and methods of preparing and using them are disclosed.

This invention relates to nickel complex compositions. In another aspectthis invention relates to methods of preparing and using nickel complexcompositions. In a further aspect this invention relates to acyl nickelcomplexes.

Methods are known in the art for the dimerization of olefinichydrocarbons in the presence of a catalyst system containing a nickelcomplex. Dimerization of propylene and other lower monoolefins continuesto be of interest in the synthesis of monomers for additionpolymerization, as intermediates in alcohol production by the oxoprocess, and as intermediates in the manufacture of plasticizers, lubeadditives, monomers for condensation polymerization, detergent basematerials, improved motor fuel and the like. This continuing interesthas established a need in the art for improved nickel complexdimerization catalysts. The extent of the dimerization, as well asstability of the resulting catalyst, is greatly dependent upon thecharacter of the components employed to produce the catalyst system. Ingeneral, substantial variations in resulting dimer product types,catalyst stability, and olefin conversion are encountered if thecharacter of the catalyst complex is varied.

It is an object of the present invention to provide heretofore unknownacyl nickel complexes.

A further object of the present invention is to provide methods forpreparing heretofore unknown acyl nickel complexes.

A still further object of this invention is to provide a process foroligomerizing monoolefins employing said heretofore unknown acyl nickelcomplexes.

Other aspects, objects, and advantages of the invention will be apparentto one skilled in the art from this disclosure and the appended claims.

In accordance with the present inventiontrans-halo(acyl)bis(triethylphosphine)nickel(II) complexes are providedwhich have the formula ##STR1## wherein X is a halogen; PEt₃ istriethylphosphine; and R is selected from the group consisting of alkylhydrocarbon radicals containing 1 to 12 carbon atoms; aryl hydrocarbonradicals containing 6 to 12 carbon atoms; substituted aryl radicalscontaining 6 to 12 carbon atoms; substituted aryl radicals containing 6to 12 carbon atoms and having as the only non-hydrocarbon substituents 1or 2 halogens selected from fluorine, chlorine, and bromine bonded tothe aromatic portion of the aryl radical; and substituted aralkylradicals containing 7 to 12 carbon atoms and having as the onlynon-hydrocarbon substituents one or more halogens selected fromfluorine, chlorine, and bromine bonded to the aromatic portion of thearalkyl radical. Examples of such complexes includetrans-chloro(1-adamantanecarbonyl)bis(triethylphosphine)nickel(II),trans-chloro(pivaloyl)bis(triethylphosphine)nickel(II),trans-chloro(4-chlorobenzoyl)bis(triethylphosphine)nickel(II),trans-chloro(3-chlorobenzoyl)bis(triethylphosphine)nickel(II),trans-chloro(benzoyl)bis(triethylphosphine)nickel(II),trans-chloro(3,3-dimethylbutanoyl)bis(triethylphosphine)nickel(II),trans-chloro(2-chlorobenzoyl)bis(triethylphosphine)nickel(II),trans-chloro(acetyl)bis(triethylphosphine)nickel(II),trans-bromo(benzoyl)bis(triethylphosphine)nickel(II),trans-fluoro(benzoyl)bis(triethylphosphine)nickel(II), andtrans-chloro(1-naphthoyl)bis(triethylphosphine)nickel(II).

One method of preparing atrans-halo(acyl)bis(triethylphosphine)nickel(II) complexes having theformula set forth in the preceding paragraph involves reaction insolution of 1,5-cyclooctadiene)bis(triethylphosphine)nickel(O), alsoreferred to herein as Ni(1,5-COD)(PEt₃)₂, with acyl halides of theformula ##STR2## wherein R and X are as described in the precedingparagraph, under reaction conditions suitable for producing thecorresponding trans-halo(acyl)bis(triethylphosphine)nickel(O) complexes.In this reaction any solvent can be employed which does not prevent theformation of the desired product. The amount of solvent needed isgenerally that amount which will insure that the reactants are in theliquid phase at the reaction temperature. One skilled in the art havingthe benefit of this disclosure can readily vary the concentration ofreactants in various suitable solvents to obtain different reactionrates and yields of products. Examples of suitable solvents includealiphatic hydrocarbons, aromatic hydrocarbons, ethers, aliphaticnitriles, aliphatic ketones, alkyl esters of aliphatic acids, andmixtures of any two or more thereof. Typical examples of solventsinclude hexane, heptane, cyclohexane, octane, benzene, toluene, xylenes,dioxane, diethyl ether, tetrahydrofuran, diethylene glycol dimethylether, acetonitrile, propionitrile, butyronitrile, acetone, methylethylketone, diethyl ketone, methyl acetate, ethyl acetate, methylpropionate, and mixtures of any two or more thereof.

The Ni(1,5-COD)(PEt₃)₂ employed can be prepared in any suitable manner.A preferred embodiment of this method of preparing the subjecttrans-halo(acyl)bis(triethylphosphine)nickel(II) complexes involvesemploying the product mixture which results on mixingbis(1,5-cyclooctadiene)nickel(O) and triethylphosphine in a suitablesolvent to produce Ni(1,5-COD)(PEt₃)₂ in situ. Suitable solvents includethose set forth above for the reaction of Ni(1,5-COD)(PEt₃)₂ and an acylhalide. According to this preferred method, the product mixturecomprising Ni(1,5-COD)(PEt₃)₂, 1,5-cyclooctadiene, and solvent iscontacted with an acyl halide as above defined to give the correspondingtrans-halo(acyl)bis(triethylphosphine)nickel(II) complex.

Any amounts of bis(1,5-cyclooctadiene)nickel(O) and triethylphosphinecan be employed which result in the formation of significant amounts ofNi(1,5-COD)(PEt₃)₂. Generally the molar ratio of the former to thelatter is in the range of about 4:1 to about 1:4, preferably about 1:2.Any temperature or pressure conditions can be employed which result inthe formation of a solution of Ni(1,5-COD)(PEt₃)₂. The general andpreferred conditions for temperature and pressure are the same as willbe set forth below for the acylation reaction.

Examples of acyl halides falling within the formula ##STR3## as abovedefined include benzoyl bromide, 4-toluoyl chloride, acetyl chloride,3-chlorobenzoyl bromide, 1-adamantanecarbonyl chloride, benzoylfluoride, 3-bromobenzoyl bromide, 3,3-dimethylbutanoyl chloride,pivaloyl chloride, 2-chlorobenzoyl chloride, 2,5-dichlorobenzoylchloride, benzoyl chloride, 2,4-dimethyl benzoyl fluoride,3-chloro-5-methyl benzoyl chloride, benzoyl iodide, 4-chlorobenzoylchloride, 3-chlorobenzoyl chloride, 1-naphthoyl chloride, and2,3-dimethyl-1-naphthoyl chloride.

Of course, two or more acyl halides can be employed to produce two ormore different corresponding products. Those skilled in the art willhowever appreciate that such a course of action can present problems ofcompeting reactions and can make recovery of the products moredifficult.

While some product may be produced at higher or lower temperaturesgenerally the temperature employed for reacting(1,5-cyclooctadiene)bis(triethylphosphine)nickel(O) and acyl halide isin the range of about -50° C. to about 100° C., and preferably is in therange of about 0° C. to about 50° C. The pressure employed is generallythat which will essentially maintain the solvent in the liquid phase atthe reaction temperature, and preferably the reaction is conducted atatmospheric pressure. While longer or shorter reaction times can beemployed, generally the reaction time is in the range of about 1 minuteto about 2 hours, preferably about 2 minutes to about 30 minutes. Alsowhile other molar ratios can be employed generally the molar ratio ofthe acyl halide, as defined above, to nickel(O) charged is in the rangeof about 5:1 to about 1:1, preferably 2:1 to about 1:1.

Preferably the acyl halide reactant should be in excess at all timesduring the mixing process to minimize the possibility of productdecarbonylation by reaction of the product with any nickel(O) speciespresent. Thus it is preferable to add the(1,5-cyclooctadiene)bis(triethylphosphine)nickel(O) or Ni(1,5-COD)₂/PEt₃ admixture to the acyl halide. Also it is preferable to (1) firstprepare separate solutions of the nickel(O) triethylphosphine complexand the acyl halide and (2) then combine these solutions to produce thetrans-halo(acyl)bis(triethylphosphine)nickel(II).

Some of the trans-halo(acyl)bis(triethylphosphine)nickel(II) complexesof this invention can also be prepared by the carbonylation of asolution of a Ni(II) complex of the formula

R'-Ni(PEt₃)₂ X under conditions sufficient to produce complexes of theformula ##STR4## wherein for each formula X is a halogen; PEt₃ istriethylphosphine; and R' is selected from the group consisting of arylhydrocarbon radicals containing 6 to 12 carbon atoms; substituted arylradicals containing 6 to 12 carbon atoms and having as the onlynon-hydrocarbon substituents 1 or 2 halogens selected from fluorine,chlorine, and bromine bonded to the aromatic portion of the arylradical; and substituted aralkyl radicals containing 7 to 12 carbonatoms and having as the only non-hydrocarbon substituents one or morehalogens selected from fluorine, chlorine, and bromine bonded to thearomatic portion of the aralkyl radical. Examples of R' groups fallingwithin the above description include phenyl, 4-tolyl, 4-chlorophenyl,2,5-dichlorophenyl, 3-bromophenyl, 2-fluorophenyl,3-chloro-5-methylphenyl, 2-tolyl, 4-bromophenyl, and 1-naphthyl.

The carbonylation reaction involves contacting the solution of thedefined nickel(II) complex reactant with an amount of carbon monoxidesufficient to convert said nickel(II) complex reactant to thecorresponding inventive acyl nickel(II) complex. Although carbonylationcan occur at higher or lower temperatures, generally the reaction isconducted with a temperature in the range of about -50° C. to about 100°C., preferably about 0° C. to about 50° C. Although the carbonylationcan occur at higher or lower pressures, the reaction is generallycarried out under an atmosphere consisting essentially of carbonmonoxide at a pressure in the range of about 1 to about 1000 psig,preferably about 5 to about 200 psig. While longer or shorter reactiontimes can be employed, generally the reaction time is in the range ofabout 1 minute to about 24 hours, preferably about 2 minutes to about 2hours.

In the carbonylation reaction, the amount of solvent employed isgenerally that which will insure that the nickel(II) complex reactant isin solution at the reaction temperature. The amount, and thus thepressure of carbon monoxide necessary for optimum production of the acylnickel(II) product under specific conditions can be readily determinedby one skilled in the art by trying various pressures. Generallyprogress of the reaction is evidenced by a drop in the pressure in thereactor.

In the carbonylation, more than one nickel(II) complex can be employed;but, this of course increases the chance for competing reactions and canrender recovery of product more difficult.

Regardless of whether thetrans-halo(acyl)bis(triethylphosphine)nickel(II) is prepared byacylation or carbonylation the product once prepared can then berecovered using any suitable techniques conventionally employed by thoseskilled in the art for recovering and purifying products contained in adiluent, i.e. precipitation, filtration and washing; or evaporation invacuo, separation of impurities by chromatography, andrecrystallization. It is thus convenient if the solvent employed is onein which the product is relatively insoluble at a temperature on theorder of about -20° C. to about -80° C. or alternatively if the solventis sufficient volatile that the product can be isolated by solventevaporation at a temperature which does not adversely affect theproduct.

The acyl nickel(II) complexes of this invention, like many of thecompounds employed as reactants in preparing them, are sensitive tooxygen and/or water to varying degrees. Therefore, the preparation anduse of these complexes should be conducted under an inert atmosphere,for example in a recirculating-atmosphere drybox providing an inertatmosphere such as argon.

The nickel(II) complexes of this invention can be used in a catalystsystem for oligomerizing monoolefins to products such as dimers. Thecatalyst system employed in the oligomerization comprises at least oneof the acyl nickel(II) complexes of the instant invention and at leastone organoaluminum halide compound represented by the formula R"_(n)AlX_(3-n), wherein each R" is a hydrocarbyl radical having from 1 to 20carbon atoms; each X is a halogen; and n is 1, 1.5, or 2.

Some specific examples of organoaluminum halide components of thecatalyst system are: methylaluminum dichloride, dimethylaluminumchloride, diethylaluminum bromide, ethylaluminum dibromide,vinylaluminum diiodide, dibutylaluminum chloride, phenylaluminumdibromide, dibenzylaluminum chloride, 4-tolylaluminum dichloride,dodecylaluminum dibromide, methylaluminum sesquichloride, and the likeand mixtures of any two or more thereof. Presently preferred aluminumcompounds are organoaluminum halides containing hydrocarbon radicalshaving 1 to 6 carbons, such as methylaluminum sesquichloride.

The catalyst components can be combined in any suitable proportions.Generally they are combined in proportions in a range of 0.5:1 to about20:1 moles of an organoaluminum halide per mole of nickel complex.Catalyst poisons in the system can be scavenged by employing evengreater proportions of the organoaluminum halide compound.

The catalyst system is prepared by combining the first and secondcomponents of the catalyst-forming admixture under suitable conditionsof time and temperature which permit the active catalyst to be formed.The two components of the catalyst system can be mixed at any suitabletemperature. Generally the catalyst is prepared at a temperature in therange of about -80° to about 100° C. for a period of time ranging from afew seconds up to several hours in the presence of a diluent in whichboth of the catalyst-forming components are at least partially soluble.Any diluent is suitable that is an inert liquid under the reactionconditions. Examples of suitable solvents or diluents are benzene,cyclohexane, chlorobenzene, methylene chloride, ethylene chloride, andthe like. However, halogenated diluents are preferred. The forming ofthe catalyst system by admixing the two components is generally carriedout in an inert atmosphere and in the substantial absence of air ormoisture. After the catalyst system is formed, it need not be isolatedbut can be added directly to the reaction zone as a solution orsuspension in its preparation medium. If desired, the components used toform the catalyst system can be separately added, in any order, to thereaction zone either in the presence or absence of the feed olefin.

Any suitable monoolefin can be oligomerized employing the just-describedcatalyst system. Generally, the monoolefins oligomerized includehydrocarbyl cyclic monoolefins having up to and including 12 carbonatoms per molecule and hydrocarbyl acyclic monoolefins having from 2 to12 carbon atoms, inclusive, where the acyclic monoolefin can be aterminal or an internal olefin, branched or unbranched. Examples ofsuitable monoolefins include, for example, ethylene, propylene,butene-1, butene-2, pentene-1, pentene-2, cyclopentene, cyclohexene,3,4,5-trimethylcyclohexene, 3-methylbutene-1, cycloheptene, hexene-2,heptene-1, cyclooctene, 4,4-dimethylheptene-2, decene-1, dodecene-1, andthe like, and mixtures of any two or more thereof. The preferredmonoolefins are those hydrocarbons having from 2 to 12 carbon atoms andno branching on a doubly bonded carbon.

The oligomerization of the monoolefin or mixture of monoolefins can takeplace at any suitable temperature. Generally the temperature is withinthe range of about -80° to about 200° C., and preferably within therange of about -10° to about 50° C. The reaction is carried out with thediluent in the liquid phase. Also any suitable pressure can be employed.Normally, it is desirable to carry out the dimerization reaction underpressures ranging from about 0 psig up to about 2000 psig and preferably20-50 psig. The oligomerization can be carried out in the presence of adiluent such as that used for the catalyst preparation if desired. Thetime of contact of the olefin with the catalyst for the oligomerizationof the olefin will vary depending upon the desired degree of conversionbut generally will be within the range from about 0.1 minute to about 20hours, preferably 5 to 120 minutes. The proportion of nickel complex toolefin feed in the reaction zone will generally be within the range ofabout 0.00001 to about 0.1 mole of nickel complex per mole of olefinfeed.

Any conventional contacting technique can be utilized for the olefinoligomerization and batchwise or continuous operations can be utilized.After the desired degree of conversion of the olefin to the dimer, theproducts so formed can be separated and isolated by conventional meanssuch as by fractionation, crystallization, adsorption, and the like. Theunconverted feed material can be recycled to the reaction zone. Ifdesired, the catalyst can be destroyed by treatment with suitabledeactivating agents such as water or alcohol, prior to the separation ofthe products.

Without further elaboration, one skilled in the art using the precedingdisclosure should be able to utilize the present invention to itsfullest extent. The following preferred specific embodiments are,therefore, to be construed as merely illustrative, and not undulylimitative of the remainder of the specification and claims in any waywhatsoever.

Unless it is indicated as otherwise the work described in the followingexamples was done at atmospheric pressure in a recirculating-atmospheredrybox providing an argon atmosphere.

Examples I-X illustrate the preparation of specific inventive acylnickel(II) complexes by acylation. Examples XI-XIII illustrate thepreparation of specific inventive acyl nickel(II) complexes bycarbonylation. Example XIV illustrates the employment of an inventiveacyl nickel(II) complex in the oligomerization of a monoolefin.

EXAMPLE I

A 125 ml erlenmeyer flask was placed in a dry box and charged with amixture of 0.55 g (2.0 mmols) of bis(1,5-cyclooctadiene)nickel(O), 5 mlof hexane and 0.48 g (4.0 mmols) of triethylphosphine. The mixturebecame homogeneous and was cooled to 5°-10° C. before the addition of0.40 g (2.0 mmols) of 1-adamantanecarbonyl chloride. After the additionof the acyl chloride, the yellow solution became brown and golden brownplatelets precipitated from the reaction mixture. The crystals wereremoved by suction filtration, washed with hexane and dried in vacuo togive 0.70 g of product [m.p. (air) 140°-142° C. dec.; m.p. (argon)145°-147° C. dec.]. (The term "dec." as used in these examples is meantto indicate that there was decomposition with the melting.) The productwas identified astrans-chloro(1-adamantanecarbonyl)bis(triethylphosphine)nickel(II) basedupon the following elemental analysis:

    ______________________________________                                                       % C  % H                                                       ______________________________________                                        Theoretical      55.95  9.19                                                  Found            57.00  8.91                                                  ______________________________________                                    

Further characterization of the above product was carried out on asample recrystallized at -78° C. from ether containing about 1 ml ofbenzene. The bronze colored crystals which formed were isolated bysuction filtration and were dried to a weight of 0.49 g [m.p. (argon)148°-149° C. dec.]. This material was identified astrans-chloro(1-adamantanecarbonyl)bis(triethylphosphine)nickel(II) basedupon the following elemental analysis:

    ______________________________________                                                       % C  % Ni                                                      ______________________________________                                        Theoretical      55.95  11.89                                                 Found            56.31  11.4                                                  ______________________________________                                    

EXAMPLE II

A small glass container equipped with a magnetic stirring bar was placedin a dry box and charged with a mixture of 0.55 g (2.0 mmols) ofbis(1,5-cyclooctadiene)nickel(O), 10 ml of hexane and 0.47 g (4.0 mmols)of triethylphosphine. After cooling this mixture to 0° C., a 0.24 g (2.0mmols) sample of pivaloyl chloride dissolved in 5 ml of cold hexane wasadded and the mixture was stirred at ambient temperature before coolingto -78° C. The red-brown platelets which formed were removed by suctionfiltration and dried to give 0.55 g of product [m.p. (argon): 73°-74° C.dec.]. The product was identified astrans-chloro(pivaloyl)bis(triethylphosphine)nickel(II) based upon thefollowing elemental analysis:

    ______________________________________                                                % C        % H    % Ni                                                ______________________________________                                        Theoretical                                                                             49.13        9.46   14.13                                           Found     49.39        9.76   14.43                                           ______________________________________                                    

EXAMPLE III

A small glass container equipped with a magnetic stirring bar was placedin a dry box and charged with 20 ml of hexane and 0.35 g (2.0 mmols) of4-chlorobenzoyl chloride. To this solution was added dropwise ahomogeneous mixture of 0.55 g (2.0 mmols) ofbis(1,5-cyclooctadiene)nickel(O) and 0.47 g (4.0 mmols) oftriethylphosphine in 10 ml of hexane. The resulting orange-red reactionmixture was cooled to -78° C. and the orange crystalline reactionproduct was removed by suction filtration and dried to give 0.63 g ofproduct [m.p. (argon): 101°-110° C.]. An additional 0.04 g of productwas obtained from the filtrate to give a total yield of 0.67 g. A samplerecrystallized from ether gave the following analysis consistent withthat expected fortrans-chloro(4-chlorobenzoyl)bis(triethylphosphine)nickel(II).

    ______________________________________                                                       % C  % H                                                       ______________________________________                                        Theoretical      48.55  7.29                                                  Found            48.56  7.34                                                  ______________________________________                                    

EXAMPLE IV

A small glass container equipped with a magnetic stirring bar was placedin a dry box and charged with 20 ml of hexane and 0.35 g (2.0 mmols) of3-chlorobenzoyl chloride. To this solution was added in a dropwisefashion a homogeneous mixture of 0.55 g (2.0 mmols) ofbis(1,5-cyclooctadiene)nickel(O) and 0.47 g (4.0 mmols) oftriethylphosphine in 10 ml of hexane. During a period of 10 minutes at25° C., the solution turned to a red-brown color and a tan precipitateformed. After removal of this precipitate by filtration, the filtratewas cooled to -78° C. to give 0.57 g of an orange-brown solid [m.p.(argon): 76°-82° C.]. Recrystallization from ether gave 0.17 g of orangecrystals [m.p. (argon): 80°-86° C.]. An additional 0.10 g of orangecrystals was isolated from the mother liquor. The elemental analysisapproximates that expected fortrans-chloro(3-chlorobenzoyl)bis(triethylphosphine)nickel(II):

    ______________________________________                                                       % C  % H                                                       ______________________________________                                        Theoretical      48.55  7.29                                                  Found            45.33  7.04                                                  ______________________________________                                    

EXAMPLE V

A small glass container equipped with a magnetic stirring bar was placedin a dry box and charged with 2.8 g (20 mmols) of benzoyl chloride in 50ml of hexane. To this solution was added in a dropwise fashion ahomogeneous mixture of 5.5 g (20 mmols) ofbis(1,5-cyclooctadiene)nickel(O) and 4.8 g (40 mmols) oftriethylphosphine in 20 ml of hexane. A precipitate that formed onmixing was dissolved by the addition of 5-10 ml of acetonitrile. Thesolution was cooled to -78° C. and the orange crystals whichprecipitated were recovered by suction filtration. The orange crystalswere dried in vacuo and subsequently combined with another crop ofcrystals from the filtrate to give a yield of 6.83 g. Recrystallizationof the product from ether at -78° C. gave 4.73 g of product (m.p.73.5°-75° C.). The elemental analysis was consistent with that expectedfor trans-chloro(benzoyl)bis(triethylphosphine)nickel(II):

    ______________________________________                                                       % C  % H                                                       ______________________________________                                        Theoretical      52.39  8.10                                                  Found            52.58  8.34                                                  ______________________________________                                    

EXAMPLE VI

A small glass container equipped with a magnetic stirring bar was placedin a dry box and charged with 0.55 g (2.0 mmols) ofbis(1,5-cyclooctadiene)nickel(O) and 0.47 g (4.0 mmols) oftriethylphosphine dissolved in 10 ml of hexane. To this solution wasslowly added 0.27 g (2.0 mmols) of 3,3-dimethylbutanoyl chloridedissolved in 5 ml of hexane. The solution was filtered and the filtratewas concentrated in vacuo and then cooled to -78° C. to cause theprecipitation of about 0.31 g of orange crystals. An additional 0.29 gof orange crystals was isolated from the mother liquor to give a totalyield of 0.60 g (m.p. 100°-101° C.). The elemental analysis wasconsistent with the structuretrans-chloro(3,3-dimethylbutanoyl)bis(triethylphosphine)nickel(II):

    ______________________________________                                                % C        % H    % Ni                                                ______________________________________                                        Theoretical                                                                             50.32         9.62  13.67                                           Found     51.36        10.11  13.80                                           ______________________________________                                    

EXAMPLE VII

A small glass container was placed in a dry box and charged with amixture of 0.35 g (2.0 mmols) of 2-chlorobenzoyl chloride in 20 mlhexane. To this solution was added in a dropwise manner a homogeneousmixture of 0.55 g (2.0 mmmols) of bis(1,5-cyclooctadiene)nickel(O) and0.47 g (4.0 mmols) of triethylphosphine in 10 ml of hexane. The solutionbecame orange-red in color and on cooling to -78° C. red-brown crystalsprecipitated. This product was recovered by suction filtration and driedin vacuo to a weight of 0.62 g [m.p. (argon) 78°-80° C. withdecarbonylation]. The elemental analysis approximates that expected fortrans-chloro(2-chlorobenzoyl)bis(triethylphosphine)nickel(II):

    ______________________________________                                                       % C  % H                                                       ______________________________________                                        Theoretical      48.55  7.29                                                  Found            42.76  6.82                                                  ______________________________________                                    

EXAMPLE VIII

A small glass container was placed in a dry box and charged with amixture of 0.16 g (2.0 mmols) of acetyl chloride in 20 ml hexane. Tothis solution was added in a dropwise manner a homogeneous mixture of0.55 g (2.0 mmols) of bis(1,5-cyclooctadiene)nickel(O) and 0.47 g (4.0mmols) of triethylphosphine in 10 ml of hexane. The solution becameyellow-brown in color and was cooled to -78° C. No crystals oftrans-chloro(acetyl)bis(triethylphosphine)nickel(II) precipitated untilthe reaction mixture was concentrated in the cold to about 10 ml andrechilled to about -78° C. Crystallization was induced by scratching theinner wall of the reactor vessel with a solid glass rod. The resultingorange-brown crystals were recovered by suction filtration of the coldreaction mixture but on warming to 25° C., the product melted on thefritted glass filter and gradually decomposed. Structure verificationwas based on an infrared spectrum with the following characteristicabsorptions (cm⁻¹): 2950 vs, 1980 vw, 1920 vw, 1640 vs, 1455 s, 1410 ms,1395 m, 1320 m, 1250 mw, 1065 ms, 1040 vs, 1010 mw, 956 w, 887 mw, 767vs, 737 w, 724 s, 708 w. This pattern of infrared absorptions isconsistent with the proposed structuretrans-chloro(acetyl)bis(triethylphosphine)nickel(II).

EXAMPLE IX

A small glass container equipped with a magnetic stirring bar was placedin a dry box and charged with 0.74 g (4.0 mmols) of benzoyl bromide in 5ml of ether at 25° C. To this solution was added dropwise a homogeneousmixture of 1.10 g (4.0 mmols) of bis(1,5-cyclooctadiene)nickel(O) and0.94 g (8.0 mmols) of triethylphosphine in 5 ml of hexane. The mixtureassumed a cloudy red-brown appearance until about 2/3 of the Ni(O)reagent had been added at which point the reaction mixture warmed andbecame a clear dark brown solution. After addition was complete, thesolution was filtered and the filtrate was cooled to -70° C. Theresulting yellow-brown crystals were suction filtered, washed with coldhexane and dried to give 0.66 g of product. Recrystallization from etherat -70° C. gave 0.36 g (m.p. 77°-80° C.) of yellow-brown crystals. Theelemental analysis is consistent with that expected fortrans-bromo(benzoyl)bis(triethylphosphine)nickel(II):

    ______________________________________                                                       % C  % H                                                       ______________________________________                                        Theoretical      47.54  7.35                                                  Found            48.28  7.25                                                  ______________________________________                                    

EXAMPLE X

A small glass container equipped with a magnetic stirring bar was placedin a dry box and charged with 0.51 g (4.0 mmols) of benzoyl fluoride in5 ml of ether at 25° C. To this solution was added in a dropwise mannera yellow-brown solution of 1.10 g (4.0 mmols) ofbis(1,5-cyclooctadiene)nickel(O) and 0.94 g (8.0 mmols) oftriethylphosphine in a mixture of 5 ml hexane and 2 ml of ether. Theresulting homogeneous mixture was cooled to -70° C. and filtered toremove a very small amount of bis(1,5-cyclooctadiene)nickel(O). Thefiltrate was concentrated in vacuo and cooled to -70° C. Brown crystalswere recovered by suction filtration, washed with cold hexane and driedto give 0.64 g (m.p. 55.5°-57° C.) oftrans-fluoro(benzoyl)bis(triethylphosphine)nickel(II). The filtrate wasstored at -35° C. for about 64 hours to give an additional 0.51 g ofproduct (m.p. 53°-57° C.). Structure verification was based on aninfrared spectrum with the following characteristic absorptions (cm⁻¹):2930 vs, 1065 s, 1575 m, 1455 s, 1415 mw, 1375 m, 1300 w, 1255 w, 1240w, 1180 w, 1145 mw, 1135 mw, 1075 w, 1035 s, 1005 w, 876 s, 783 mw, 767s, 727 s, 701 s, 676 mw. This pattern of infrared absorptions isconsistent with the proposed structuretrans-fluoro(benzoyl)bis(triethylphosphine)nickel(II).

EXAMPLE XI

A small Diels-Alder pressure tube was placed in a dry box and chargedwith 0.81 g (2.0 mmols) oftrans-chloro(phenyl)bis(triethylphosphine)nickel(II) and 5 ml of hexane.The tube was capped and removed from the dry box. The tube was partiallyflushed with carbon monoxide, pressured to 15 psig with carbon monoxideand then was allowed to stand at ambient temperature for about 14 hours.During this period of time orange crystals had precipitated from thesolution. After venting the system, the tube was returned to the drybox, cooled to -72° C. and the orange crystals were removed by suctionfiltration, washed with ether and dried in vacuo. The orange crystalsweighed 0.70 g and exhibited a melting point of 73°-75° C. The orangecolored product possessed an infrared spectrum (Nujol) which wasidentical to that exhibited by thetrans-chloro(benzoyl)bis(triethylphosphine)nickel(II) prepared (seeExample V) by the reaction of benzoyl chloride with a mixture ofbis(1,5-cyclooctadiene)nickel(O) and triethylphosphine in hexanesolution.

EXAMPLE XII

A small aerosol compatibility bottle equipped with a magnetic stirringbar was placed in a dry box and charged with 1.05 g (2.38 mmols) oftrans-chloro(2-chlorophenyl)bis(triethylphosphine)nickel(II) and 10 mlof hexane. The bottle was capped and removed from the dry box. Thebottle was pressured to 200 psig with carbon monoxide and on stirringthe solution turned orange, absorbed some carbon monoxide and an orangecolored precipitate appeared. After standing at ambient temperature forabout 14 hours, the reactor bottle was vented, returned to the dry boxand cooled to -20° C. to complete the precipitation. An orange-coloredprecipitate (0.80 g) contaminated with black and green impurities wasisolated by suction filtration and exhibited an infrared spectrum(Nujol) identical to that of thetrans-chloro(2-chlorobenzoyl)bis(triethylphosphine)nickel(II) preparedby contacting 2-chlorobenzoyl chloride with a mixture ofbis(1,5-cyclooctadiene)nickel(O) and triethylphosphine (see ExampleVII).

In an attempt to purify the above product, the solid was dissolved inether and filtered to remove impurities. During this time the ethersolution bubbled perhaps due to decarbonylation and on cooling theethereal mixture to -72° C., a mixture of orange and yellow crystalsprecipitated. The entire mixture was transferred to an aerosolcompatibility bottle, pressured to 200 psig with carbon monoxide andallowed to stand at ambient temperature for about 64 hours. The yellowsolution was decanted and on cooling to -72° C., orange crystals (0.1 g,m.p. 84°-86.5° C.) separated from solution. These orange crystalsexhibited an infrared spectrum (Nujol) identical to that of thetrans-chloro(2-chlorobenzoyl)bis(triethylphosphine)nickel(II) of ExampleVII and gave the following elemental analysis:

    ______________________________________                                                % C  % H         % Cl    % Ni                                         ______________________________________                                        Theoretical                                                                             48.55  7.29        15.09 12.49                                      Found     49.75  7.96        15.38 12.71                                      ______________________________________                                    

The orange crystalline product decarbonylated completely on heating toabout 105° C. to yieldtrans-chloro(2-chlorophenyl)bis(triethylphosphine)nickel(II) with amelting point in the range of 85°-88° C.

EXAMPLE XIII

A small Diels-Alder pressure tube equipped with a magnetic stirring barwas placed in a dry box and charged with 0.44 g (1.0 mmol) oftrans-chloro(3-chlorophenyl)bis(triethylphosphine)nickel(II) and 5 ml ofhexane. The tube was capped, removed from the dry box and pressured to16 psig with carbon monoxide. On stirring a rapid uptake of carbonmonoxide was evidenced by the decrease in pressure to about 3 psig in afew minutes. The tube was repressured to 16 psig with carbon monoxideand allowed to stand at ambient temperature for about 14 hours. Duringthis time period orange crystals precipitated from solution. Afterventing the system, the tube was returned to the dry box, cooled to -72°C. and orange crystals were removed by suction filtration, washed withcold hexane and dried in vacuo. The orange crystals weighed 0.43 g [m.p.(under argon) 83°-88° C.] and possessed an infrared spectrum (Nujol)identical to that exhibited by the sample oftrans-chloro(3-chlorobenzoyl)bis(triethylphosphine)nickel(II) preparedin Example IV. The orange crystals gave the following elemental analysiswhich is consistent with the above proposed structure:

    ______________________________________                                                % C  % H         % Cl    % Ni                                         ______________________________________                                        Theoretical                                                                             48.55  7.29        15.09 12.49                                      Found     49.20  7.85        15.64 12.89                                      ______________________________________                                    

EXAMPLE XIV

An oven-dried 9 oz. glass bottle reactor equipped with a magneticstirring bar was charged with a mixture of 0.05 g (0.1 mmol) oftrans-chloro(4-chlorobenzoyl)bis(triethylphosphine)nickel(II) and 20 mlof chlorobenzene. The bottle was capped and then sequentially flushedfor 1 hour intervals with argon and propylene. The capped bottle reactorwas then cooled in an ice-salt bath for 5 minutes before pressuring thesystem to 30 psig with propylene. The system was maintained in the coldbath, vented to 5 psig, and 0.70 ml (0.70 mmol) of methylaluminumsesquichloride was added by syringe as a 1 M chlorobenzene solution tothe stirred reaction mixture. The bottle was pressured to and maintainedat 30 psig with propylene and the stirred reaction mixture was kept inthe cold bath for 1 hour. At this time the bottle was vented and 10 mlof saturated aqueous sodium chloride solution was added. The aqueous andorganic phases were separated and the aqueous phase was extracted onetime with 5 ml of chlorobenzene. The combined organic phases were driedover anhydrous magnesium sulfate. Distillation of the dried organicphase gave 29.35 g of colorless liquid with a boiling range of 60°-68°C.

A 2.0 g sample of the above liquid was hydrogenated over 0.1 g of PtO₂under 20-90 psig of H₂ for 18 hours. The hydrogenated product wasexamined by glpc on a 20 foot × 1/8 inch isoquinoline column at 25° C.to give the following analysis:

    ______________________________________                                        Component        Area %                                                       ______________________________________                                        2,3-dimethylbutane                                                                             19.8                                                         2-methylpentane  66.9                                                         n-hexane         13.3                                                         ______________________________________                                    

This demonstrates that dimers were formed and it further indicates theskeletal structure of the dimers.

The terms and expressions employed in this disclosure are used as termsof description and are not intended to be unduly limiting. There is nointention in the use of such terms and expressions of excluding anyequivalents of features shown and described or portions thereof.Further, it should be recognized that various modifications are possiblewithin the scope of the following claims.

What is claimed is:
 1. Atrans-halo(acyl)bis(triethylphosphine)nickel(II) complex of the formula##STR5## wherein X is halogen; PEt₃ is triethylphosphine; and R isselected from the group consisting of alkyl hydrocarbon radicalscontaining 1 to 12 carbon atoms; aryl hydrocarbon radicals containing 6to 12 carbon atoms; substituted aryl radicals containing 6 to 12 carbonatoms and having as the only non-hydrocarbon substituents 1 or 2halogens selected from fluorine, chlorine, and bromine bonded to thearomatic portion of the aryl radical; and substituted aralkyl radicalscontaining 7 to 12 carbon atoms and having as the only non-hydrocarbonsubstituents one or more halogens selected from fluorine, chlorine, andbromine bonded to the aromatic portion of the aralkyl radical.
 2. Anickel(II) complex according to claim 1 wherein R is a 1-adamantylradical and X is a chlorine radical.
 3. A nickel(II) complex accordingto claim 1 wherein R is a tertiary butyl radical and X is a chlorineradical.
 4. A nickel(II) complex according to claim 1 wherein R is a4-chlorophenyl radical and X is a chlorine radical.
 5. A nickel(II)complex according to claim 1 wherein R is a 3-chlorophenyl radical and Xis a chlorine radical.
 6. A nickel(II) complex according to claim 1wherein R is a phenyl radical and X is a chlorine radical.
 7. Anickel(II) complex according to claim 1 wherein R is a2,2-dimethylpropyl radical and X is a chlorine radical.
 8. A nickel(II)complex according to claim 1 wherein R is a 2-chlorophenyl radical and Xis a chlorine radical.
 9. A nickel(II) complex according to claim 1wherein R is a methyl radical and X is chlorine radical.
 10. Anickel(II) complex according to claim 1 wherein R is a phenyl radicaland X is a bromine radical.
 11. A nickel(II) complex according to claim1 wherein R is a phenyl radical and X is a fluorine radical.
 12. Anickel(II) complex according to claim 1 wherein X is a chlorine radical.13. A nickel(II) complex according to claim 1 wherein X is a bromineradical.
 14. A nickel(II) complex according to claim 1 wherein X is afluorine radical.
 15. A process for preparing atrans-halo(acyl)bis(triethylphosphine)nickel(II) complex of the formula##STR6## wherein X is halogen; PEt₃ is triethylphosphine; and R isselected from the group consisting of alkyl hydrocarbon radicalscontaining 1 to 12 carbon atoms; aryl hydrocarbon radicals containing 6to 12 carbon atoms; substituted aryl radicals containing 6 to 12 carbonatoms and having as the only non-hydrocarbon substituents 1 or 2halogens selected from fluorine, chlorine, and bromine bonded to thearomatic portion of the aryl radical; and substituted aralkyl radicalscontaining 7 to 12 carbon atoms and having as the only non-hydrocarbonsubstituents one or more halogens selected from fluorine, chlorine, andbromine bonded to the aromatic portion of the aralkyl radical,comprising reacting in solution(1,5-cyclooctadiene)bis(triethylphosphine)nickel(O) and an acyl halideof the formula ##STR7## wherein R and X are as above defined, underreaction conditions suitable for producing saidtrans-halo(acyl)bis(triethylphosphine)nickel(II) complex.
 16. A processaccording to claim 15 wherein a solution of(1,5-cyclooctadiene)bis(triethylphosphine)nickel(O) is added to asolution of said acyl halide.
 17. A process according to claim 16wherein the solution of(1,5-cyclooctadiene)bis(triethylphosphine)nickel(O) that is added is theproduct mixture which results when bis(1,5-cyclooctadiene)nickel(O) andtriethylphosphine are reacted in a suitable solvent to produce saidnickel(O) complex.
 18. A process according to claim 15 wherein thesolution of (1,5-cyclooctadiene)bis(triethylphosphine)nickel(O) that isreacted with said acyl halide is the product mixture which results whenbis(1,5-cyclooctadiene)nickel(O) and triethylphosphine are reacted in asuitable solvent to produce said nickel(O) complex.
 19. A processaccording to claim 15 wherein the molar ratio of said acyl halidereactant to nickel(O) is in the range of about 5:1 to about 1:1 and thetemperature for the reaction is in the range of about -50° C. to about100° C.
 20. A process according to claim 15 wherein saidtrans-halo(acyl)bis(triethylphosphine)nickel(II) complex is isolated byprecipitation from the reaction mixture.
 21. A process for preparing atrans-halo(acyl)bis(triethylphosphine)nickel(II) complex of the formula##STR8## wherein X is a halogen; PEt₃ is triethylphosphine; and R' isselected from the group consisting of aryl hydrocarbon radicalscontaining 6 to 12 carbon atoms; substituted aryl radicals containing 6to 12 carbon atoms and as the only non-hydrocarbon substituents 1 or 2halogens selected from fluorine, chlorine, and bromine bonded to thearomatic portion of the aryl radical; and substituted aralkyl radicalscontaining 7 to 12 carbon atoms and as the only non-hydrocarbonsubstituents one or more halogens selected from fluorine, chlorine, andbromine bonded to the aromatic portion of the aralkyl radical, saidprocess comprising reacting a solution of nickel complex of the formulaR'--Ni(PEt₃)₂ X, wherein R', PEt₃, and X are as defined above, withcarbon monoxide under conditions sufficient to produce saidtrans-halo(acyl)bis(triethylphosphine)nickel(II) complex.
 22. A processaccording to claim 21 wherein said R'--Ni(PEt₃)₂ X is reacted withcarbon monoxide under an atmosphere consisting essentially of carbonmonoxide at a pressure in the range of about 1 to about 1000 psig and ata temperature in the range of about -50° C. to about 100° C.
 23. Aprocess according to claim 22 wherein saidtrans-halo(acyl)bis(triethylphosphine)nickel(II) complex is isolated byprecipitation from the reaction mixture.
 24. A process according toclaim 19 wherein the solution of(1,5-cyclooctadiene)bis(triethylphosphine)nickel(O) is the productmixture which results when bis(1,5-cyclooctadiene)nickel(O) andtriethylphosphine are reacted in a molar ratio of about 1 to 2 in asuitable solvent to produce said nickel (O) complex and wherein themolar ratio of acyl halide to said(1,5-cyclooctadiene)bis(triethylphosphine)nickel(O) is in the range of2:1 to about 1:1 and wherein said nickel(O) complex and the acyl halideare reacted at a temperature in the range of about 0° C. to about 50° C.25. A process according to claim 24 wherein said acyl halide is1-adamantanecarbonyl chloride.
 26. A process according to claim 24wherein said acyl halide is pivaloyl chloride.
 27. A process accordingto claim 24 wherein said acyl halide is 4-chlorobenzoyl chloride.
 28. Aprocess according to claim 24 wherein said acyl halide is3-chlorobenzoyl chloride.
 29. A process according to claim 24 whereinsaid acyl halide is benzoyl chloride.
 30. A process according to claim24 wherein said acyl halide is dimethylbutanoyl chloride.
 31. A processaccording to claim 24 wherein said acyl halide is 2-chlorobenzoylchloride.
 32. A process according to claim 24 wherein said acyl halideis acetyl chloride.
 33. A process according to claim 24 wherein saidacyl halide is benzoyl bromide.
 34. A process according to claim 24wherein said acyl halide is benzoyl fluoride.
 35. A process according toclaim 22 wherein said nickel complex istrans-chloro(phenyl)bis(triethylphosphine)nickel(II).
 36. A processaccording to claim 22 wherein said nickel complex istrans-chloro(2-chlorophenyl)bis(triethylphosphine)nickel(II).
 37. Aprocess according to claim 22 wherein said nickel complex istrans-chloro(3-chlorophenyl)bis(triethylphosphine)nickel(II).